Dist API specific core-for-system-modules

Previously, the dist only contained a core-for-system-modules.jar for
the public API. This change adds API specific directories containing a
core-for-system-modules.jar file for each of the following APIs:
* public
* module-lib

Bug: 204189791
Test: rm -fr out/dist
      m sdk dist
      find out/dist -name core-for-system-modules.jar
      - outputted the following:
      out/dist/core-for-system-modules.jar
      out/dist/system-modules/module-lib/core-for-system-modules.jar
      out/dist/system-modules/public/core-for-system-modules.jar
Change-Id: Id1845926e2085f70d58e9fc22e9c11cb3d62b919